Merck MRK +0.09% & Co. halted development of a pill combining its diabetes drug Januvia with a generic version of the widely used cholesterol fighter Lipitor, citing unspecified business reasons. The Whitehouse Station, N.J., company discontinued development of MK-0431E, which Merck had previously planned to submit for regulatory approval in 2014. Merck spokeswoman Pam Eisele said Tuesday the decision isn't related to any safety concerns about the two drugs. It is the second time in recent months that Merck has stopped development of a combination drug that includes a cholesterol treatment. Merck also has abandoned MK-0524B, a drug that included niacin and simvastatin, saying market conditions had become less favorable. Januvia, which contains the active ingredient sitagliptin, is Merck's best-selling drug, generating $2.95 billion in sales for the first nine months of this year. It is a once-daily tablet to treat Type 2 diabetes by helping to lower blood-sugar levels. Since Januvia went on sale in 2006, Merck has introduced new products combining it with other drugs. Last year, for instance, the U.S. Food and Drug Administration approved Juvisync, a single-pill combination of Januvia and simvastatin, a so-called statin drug that lowers bad cholesterol.